Question

An aeroplane moving horizontally with a speed of 720 km/h drops a food packet, while flying at a height of 396.9 m. The time taken by a food packet to reach the ground and its horizontal range is $(Takeg=9.8m/se{c}^2)$

• A. 3 sec and 2000 m
• B. 5 sec and 500 m
• C. 8 sec and 1500 m
• D. 9 sec and 1800 m

Answer 1

The correct option is D 9 sec and 1800 m


$Timeofdescentt=\sqrt{\frac{2h}{g}}=\sqrt{\frac{2\times 396.9}{9.8}}\Rightarrow t=9secandhorizontaldistanceS=u\times tS=\left(\frac{720\times 5}{18}\right)\times 9=1800m$